Perhaps you should try some spelling variations:
ban thanh » ban hang
thanh duc » thach duc, than duc, thinh duc
va thanh » gia thanh, va tinh, le thanh
ban hanh » ban hang
vu sach » vu bach, su sach, vu khach
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((ty nang) OR (ky nang)) xa hoi. hieu va thanh duc ((ban thanh) or (ban hanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((ty nang) OR (ky nang)) xa hoi. hieu va thanh duc ((ban thanh) OR (ban hanh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((ty nang) OR (ky nang)) xa hoi. hieu va thanh duc ((ban thanh) or (ban hanh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ((ty nang) OR (ky nang)) xa hoi. hieu va thanh duc ((ban thanh) or (ban hanh)) dai cua tre*.